There is a wide choice of surfactants currently available to the detergent manufacturer when formulating compositions in order to achieve the desired performance benefits.
A particularly desirable performance benefit for detergent compositions is good greasy and oily soil removal over a wide spectrum of temperatures. In order to achieve such desired performance benefits, the detergent manufacture has found it necessary to increase the amount of surfactant incorporated into detergent compositions. As a result the compositions have also tended to become more compact formulations, which is also in line with current trends to produce more compact formulations to reduce the environmental impact.
The sudsing profile of a detergent composition is also an important factor to be considered by the detergent manufacturer. It is generally considered that high sudsing is not a desirable feature of a laundry detergent composition for laundering conducted in automatic washing machines. However, high levels of surfactant in a detergent composition usually results in an increase in the sudsing of the detergent composition. This problem is particularly acute if the surfactant system comprises high levels of anionic surfactant. Thus, in order to control the suds profile, such compositions require the addition of a suds suppressor. However, the suds suppressors currently available are generally expensive and also provide no other performance benefit to the composition other than suds suppression. Therefore, it is desirable that their presence is minimised.
Thus, it is an aim of the present invention to provide a surfactant system which provides the dual performance benefits of excellent cleaning performance and providing suds suppression.
It has now been found that this objective can be achieved by the use of certain branched hydrolysable anionic compounds and detergent compositions as described herein. The anionic compounds of the present invention readily hydrolyse in the wash liquor and these hydrolysis products then act as suds suppressors. The hydrolysis products can thus act to suppress the sudsing produced by other surfactants which may be preferred components of the detergent composition. Of particular benefit is that the hydrolysis products tend to be formed in the latter stages of the washing process, when sudsing is at its greatest and suds suppression is most required. Furthermore, another advantage of the presence of the suds suppressing hydrolysis products, is that the amount of additional suds suppressor required in the formulation is reduced. Thus, the anionic compounds of the present invention have a dual function as a component of a surfactant system providing improved cleaning and as precursors of suds suppression agents in detergent compositions.
A further advantage of the anionic compounds of the present invention is that they are also low sudsing compounds per se.
Liquid detergent compositions comprising branched alkoxylated anionic surfactants for use as suds suppressors have been disclosed in European patent application number 93870123.2.